I’m sure it’s a complete gut job.

I think the best thing to do is take all the information and filter it for yourself and see what type of strategies align with your finances, personal viewpoint, and gut feeling. 

My gut tells me I'm missing something.

My gut tells me that there would be pretty good stock for flipping.

Do you determine your next investment by strictly abiding by these rules or you go off a bit with your instinct?

Depends on house size, location, 2 versus 1 story, etc.The only fixed I could offer is closing costs (real estate agent fees) which is usually 6% of the ARV or sale price.Anything else would be ballpark numbers like roof, foundation, kitchen/bath gut/remodel, paint interior/exterior, etc.Roof: $7K - $12K (But depends on the type of roof and if plywood needs replacing or if there are more than 1 layers of roofing that have to be removed.Foundation: $1K - $8KKitchen (total gut): $8K - $15K for average 10x10Bath (total gut): $3K - $15K depending on whether 3 piece, 4 piece or master bathInterior Paint (whole house including baseboards/trim): $1.25 - $1.75 per sq.ft.Exterior Paint (whole house): $2.00 - $2.50 per sq.ft.Note on painting: It's based on sq.ft. of house and 8 foot walls.

On projects where the scope is full gut and rebuild, there are few surprises that can come up so the contingency may go untouched.

It's set up pretty much the exact same way as my current 2-unit and I have all my costs documented on that project where I touched almost everything (roof, electrical, appliances, flooring, furnace, water heaters, etc) without gutting it out. 

One is gutting the bathroom another is just putting in a new floor and throne.  

My gut says it takes more when you factor in expenses beyond mortgage.